Answer:
72 cupcakes
Step-by-step explanation:
Morgan can make 4 cupcakes with one cup of flour. She has 18 cups of flour and suppose she can make x cupcakes, then
1 cup of flour - 4 cupcakes
18 cups of flour - x cupcakes
Write a proportion:

Cross multiply:

im sorry but i cant seem to open your image?
An inverse operation reverses the effect of another operation. Answer is C
Hope this picture helps! ;) Ignore the stuff around it ($12 or the triangle)